1. Field of the Invention
The present invention pertains to chemical processes that improve contact lenses, and specifically to a process that yields gas permeable contact lenses which serve as a surface site for a chemical reaction that yields water and oxygen, thereby enriching and lubricating the area between the contact lens and the eye.
2. Description of the Prior Art
Gas permeable contact lenses replaced hard lenses because they allow gases such as oxygen to pass through the plastic. Although one of the most noticeable features of gas permeable lenses is that they do not typically break or tear as easily as soft contact lenses, one of the primary beneficial features of these types of lenses are their gas permeability, hence their name. Allowing sufficient amounts of oxygen to pass through the lenses to the cornea of the wearer helps eliminate several problems that afflict soft lens and ordinary hard lens wearers, such as Corneal edema (swelling of the cornea), etc. In addition, some other applications and benefits of gas permeable contact lenses include: correction of special vision problems, post-surgical treatment, superior visual acuity and health benefits afforded by the lenses.
Prior art pertaining to gas permeable contact lenses include the following. U.S. Pat. No. 4,822,864 to Chen discloses a gas permeable contact lens and method and materials for its manufacture. U.S. Pat. No. 5,610,252 to Bambury et al. discloses vinyl carbonate and vinyl carbamate contact lens material monomers. U.S. Pat. No. 5,258,490 to Chang discloses a non-irritating soft gas permeable contact lens and process for producing same. None of the prior art teach a process for producing gas permeable contact lenses similar to the process of the present invention.
Consequently, the primary object of the present invention is to provide a process that produces gas permeable contact lenses that have increased oxygen permeability and flow through the lenses, as well as increased moisture between the lens and the cornea.